1. Field of the Disclosure
The features herein relate to a method of manufacturing a liquid discharge head which is configured to discharge liquid, a liquid discharge head which is configured to discharge liquid and an ink-jet printer including the liquid discharge head.
2. Description of the Related Art
A known ink-jet head includes a flow channel unit provided with a plurality of pressure chambers formed on an upper surface thereof, and actuator units fixed with heat cured adhesive agent on the upper surface of the flow channel unit so as to cover the openings of the pressure chambers. The actuator units includes a plurality of laminated piezoelectric layers, a plurality of individual electrodes arranged on the outermost piezoelectric layer so as to oppose the pressure chambers, and a common electrode arranged between the outermost piezoelectric layer and the next piezoelectric layer. The individual electrodes and the common electrode are electrically connected to a flexible printed circuit (FPC) including a driver IC mounted thereon. Driving signals assuming a ground potential and a positive potential alternately according to an image pattern to be printed are supplied from the driver IC to the individual electrodes. Signals maintained at the ground potential are supplied to the common electrode. Accordingly, portions of the piezoelectric member opposing the pressure chambers are displaced, and a pressure is applied to ink in the pressure chambers, and the ink is discharged from nozzles to form a desired image.
In the above-described ink-jet head, individual lands are projected from the individual electrodes respectively. The individual electrodes and the FPC are electrically connected via the individual lands. A surface electrode connected to the common electrode is provided on the outermost piezoelectric layer in the same manner as the individual electrodes. The common electrode and the FPC are electrically connected via a common bump on the surface electrode. The surface electrode and the common bump are arranged in the vicinity of an end portion of the upper surface of the piezoelectric layer to avoid the plurality of individual electrodes. When manufacturing the ink-jet head, heat cured adhesive agent is applied on the upper surface of the prefabricated flow channel unit. Then, the actuator units are placed on the heat cured adhesive agent, and heated while being pressurized against the flow channel unit using a flat-panel-shaped jig. In this manner, the heat cured adhesive agent between these members is cured, such that the flow channel unit and the actuator units are fixed.
However, the surface electrode and the individual electrodes may be varied in thickness, because they are configured by baking conductive paste screen printed into a predetermined pattern. The thickness of the heat cured adhesive agent may be varied. When the thickness of the heat cured adhesive agent varies, the pressure to be applied to the ink in the pressure chambers may vary, and the quality of printed images may be lowered.